73 research outputs found
Higher Poincare Lemma and Integrability
We prove the non-abelian Poincare lemma in higher gauge theory in two
different ways. The first method uses a result by Jacobowitz which states
solvability conditions for differential equations of a certain type. The second
method extends a proof by Voronov and yields the explicit gauge parameters
connecting a flat local connective structure to the trivial one. Finally, we
show how higher flatness appears as a necessary integrability condition of a
linear system which featured in recently developed twistor descriptions of
higher gauge theories.Comment: 1+21 pages, presentation streamlined, section on integrability for
higher linear systems significantly improved, published versio
Effects of source and seasonal variations of natural organic matters on the fate and transport of CeO2 nanoparticles in the environment
Natural organic matter (NOM) affects the stability and transport of nanoparticles (NPs) in natural waters by modifying their physiochemical properties. Source location, and seasonal variations, influence their molecular, physical and electrical charge properties. To understand the variations of NOM on the mobilization of NPs, large volumes of water were collected fromthe Ohio River (OR) over winter and summer seasons and dissolved NOMs were concentrated. The chemical and structural differences of these NOMs were compared with the Suwannee River humic acid (SRHA) SRHA using 1H and 13C nuclear magnetic resonance spectroscopy, and Fourier transforms infrared (FTIR) spectroscopy. Thermal analysis and FTIR confirmed that differences in composition, structure, and functional groups are a result of SRHA fractionation compared to wholemolecule OR-NOM. The influence of OR-NOMs on the surface charge of CeO2NPs and the effects on the transport and retention in a three-phase (deposition-rinse-re-entrainment) sand-packed columns were investigated at CeO2 NPs initial concertation of 10 ppm, pH 6.8, increasing ionic strength (3, 5, and 10 mM), retention time of 1 min, and increasing NOM concentration (1, 5, and 10 ppm). The summer OR-NOM showed higher stabilization and mobilization effect on the CeO2 than the winter NOM; while their effect was very different form the SRHA. The stabilization of NPs is attributed to both electrostatic and steric effects. The differences in the chemical structure of the complex and heterogeneous NOMs showed disparate reactivity and direct impact on CeO2-NPs stability. Using SRHA to study the effect of NOMfor drinkingwater related assessment does not sufficiently represent the natural conditions of the environment
Comparative Study on the Performance of Anaerobic and Aerobic Biotrickling Filter for Removal of Chloroform
Use of biotrickling filter (BTF) for gas phase treatment of volatile trihalomethanes (THMs) stripped from water treatment plants could be an attractive treatment option. The aim of this study is to use laboratory-scale anaerobic BTF to treat gaseous chloroform (recalcitrant to biological transformation) as a model THM and compare results with aerobic BTF. Additional investigations were conducted to determine the microbial diversity present within the BTFs. Chloroform is a hydrophobic volatile THM known to be difficult to biodegrade. To improve the degradation process, ethanol was used as a cometabolite at a different ratio to chloroform. The experimental plan was designed to operate one BTF under anaerobic condition and the other one under aerobic acidic condition. Higher elimination capacity (EC) of 0.23 ± 0.01 g/[m3·h] was observed with a removal efficiency of 80.9% ± 4% for the aerobic BTF operating at pH 4 for the concentration ratio of 1:40 chloroform to ethanol. For similar ratio, the anaerobic BTF supported lower removal efficiency of 59% ± 10% with corresponding lower EC of 0.16 ± 0.01 g/[m3·h]. Carbon recovery acquired for anaerobic and aerobic BTFs was 59% and 63%, respectively. The loading rate for chloroform on both BTFs was 0.27 g/[m3·h] (per m3 of filter bed volume). Variations of the microbial community were attributed to degradation of chloroform in each BTF. Azospira oryzae and Azospira restrica were the dominant bacteria and potential candidates for chloroform degradation for the anaerobic BTF, whereas Fusarium sp. and Fusarium solani were the dominant fungi and potential candidates for chloroform degradation in the aerobic BTF
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Investigation of Microalgae Co-Cultures for Nutrient Recovery and Algal Biomass Production from Dairy Manure
Treatment of waste streams using algae can minimize eutrophication by removing inorganic nutrients while producing biomass which can be used for biofuels, animal feed, and fertilizer production. While there are many studies that report the growth of individual algal strains in different media, there are relatively few studies that examine the performance of algae coculture. The objective of this research was to determine the growth parameters and nutrient sequestration profiles of Chlorella vulgaris, Scenedesmus dimorphus, and their coculture in wastewater from a dairy facility at two dilutions (10% and 25%). Average specific growth rates (and biomass concentrations) the S. dimorphus, C. vulgaris, and their coculture were 0.263 d⁻¹ (0.290±0.059 g/L), 0.063 d⁻¹ (0.145±0.011 g/L), and 0.250 d⁻¹ (0.400±0.060 g/L) d⁻¹ at 10% manure, and 0.232 d⁻¹ (0.543±0.149 g/L), 0.234 d⁻¹ (0.364±0.113 g/L), and 0.289 d⁻¹ (0.612±0.255 g/L) at 25% manure, respectively. Based on the results it was evident that the strains S. dimorphus and C. vulgaris have different capacities for accumulation of biomass production (S. dimorphus is higher), lipid accumulation (S. dimorphus is higher), chlorophyll (C. vulgaris is higher), total suspended solids (TSS) (C. vulgaris is higher), and volatile suspended solids (VSS) (S. dimorphus is higher). It was found that mixed coculture had higher biomass growth, specific growth rate, and removal efficiency of nitrogen, phosphorous, and TSS for the 25% dairy wastewater. The results were similar for 10% dairy wastewater except for the specific growth rate and nitrogen removal efficiency which were higher for the S. dimorphus monoculture. These capacities can be leveraged in mixed coculture to achieve higher treatment efficiencies compared to monocultures. The results can inform managers of agricultural and municipal wastewater facilities as they make decisions about whether to include algal technology in future upgrades and expansion.This is the publisher’s final pdf. The published article is copyrighted by the American Society of Agricultural and Biological Engineers and can be found at: http://elibrary.asabe.org/toc_landing.asp?conf=aeaj.Keywords: Scenedesmus dimorphus, Wastewater, Phosphate removal, Nitrate removal, Microalgae coculture, Chlorella vulgari
Higher Structures, Self-Dual Strings and 6d Superconformal Field Theories
I summarize and discuss some recent results on formulating actions of
six-dimensional superconformal field theories using the language of higher
gauge theory. The latter guarantees mathematical consistency of our
constructions and we review crucial aspects of this framework, such as
-algebras and corresponding kinematical data given by higher
connections. We then show that there is a mathematically consistent non-Abelian
extension of the self-dual string equation which satisfies many physical
expectations. Our construction favors a particular higher gauge group leading
us to higher principal bundles known as string structures. Using these, we
manage to formulate a six-dimensional action which shares many properties with
the famous -theory but also still differs from it in some key points.Comment: 16 pages, Contribution to Proceedings of LMS/EPSRC Durham Symposium
Higher Structures in M-Theory, August 201
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Targeted Nanocarriers for Systemic Delivery of IRAK4 Inhibitors to Inflamed Tissues
Persistent and uncontrolled inflammation is the root cause of various debilitating diseases. Given that interleukin-1 receptor–associated kinase 4 (IRAK4) is a critical modulator of inflammation, inhibition of its activity with selective drug molecules (IRAK4 inhibitors) represents a promising therapeutic strategy for inflammatory disorders. To exploit the full potential of this treatment approach, drug carriers for efficient delivery of IRAK4 inhibitors to inflamed tissues are essential. Herein, the first nanoparticle-based platform for the targeted systemic delivery of a clinically tested IRAK4 inhibitor, PF-06650833, with limited aqueous solubility (57 μg mL-1) is presented. The developed nanocarriers increase the intrinsic aqueous dispersibility of this IRAK4 inhibitor by 40 times. A targeting peptide on the surface of nanocarriers significantly enhances their accumulation after intravenous injection in inflamed tissues of mice with induced paw edema and ulcerative colitis when compared to non-targeted counterparts. The delivered IRAK4 inhibitor markedly abates inflammation and dramatically suppresses paw edema, mitigates colitis symptoms, and reduces proinflammatory cytokine levels in the affected tissues. Importantly, repeated injections of IRAK4 inhibitor-loaded nanocarriers have no acute toxic effect on major organs of mice. Therefore, the developed nanocarriers have the potential to significantly improve the therapeutic efficacy of IRAK4 inhibitors for different inflammatory diseases
Generalized higher gauge theory
We study a generalization of higher gauge theory which makes use of
generalized geometry and seems to be closely related to double field theory.
The local kinematical data of this theory is captured by morphisms of graded
manifolds between the canonical exact Courant Lie 2-algebroid
over some manifold and a semistrict gauge Lie 2-algebra. We discuss
generalized curvatures and their infinitesimal gauge transformations. Finite
gauge transformation as well as global kinematical data are then obtained from
principal 2-bundles over 2-spaces. As dynamical principle, we consider first
the canonical Chern-Simons action for such a gauge theory. We then show that a
previously proposed 3-Lie algebra model for the six-dimensional (2,0) theory is
very naturally interpreted as a generalized higher gauge theory.Comment: 24 pages, minor corrections, typos fixed, published versio
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